> with anti-spam measures making it almost impossible to self-host, and privileged delivery mechanisms like push notifications that require closed APIs to use.
There are anti-spam measures that don't require locking down protocols. Ideally, a user's feed would only consist of message boards they subscribe to. Similarly, message boards could limit posting to subscribed users, approved users, paying users, or those users with a "certificate" proving their human - the latter would be akin to certificate authorities we have today who assign certificates to websites.
> It's generally not in the interest of commercial providers to use open protocols.
Not to derail, but that's the capitalist's contradiction: a capitalist points to competition as a theoretical advantage of capitalism, but then in practice does everything to eliminate it.